Improvement in treadles for machinery



geiten' tate gatmt @fitte Letters Patent No. 79,572, dated July 7, 1868.

IMPROVEMBT IN TREADLES FOR MACHINERY.

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TO ALL WHOM IT MAY CONCERN:

v Be it known that I, ALONZO HITCHCOCK, of the city and State of NewYork, have invented a. new and improved Mode of Producing a RotaryMotion in Machinery, wherein it is necessary to produce such motion bytaking hold of a. crank-pin, or its equivalent` I The nature of myinvention consists in providing two pitmen or connection-rods, two endsof which engage or connect on the same crank-pin, while the other twoends diverge more or less, and connect with two separate and independenttrcadles or levers, to operate a sewing-machine or analogous machines,so that each foot constitutes a separate driving-power.

By this arrangement the crank-pin will form the apex of a triangle, thetwo pitmen forming two legs of the triangle, while the points at ,whichthe lower ends of the pitmen unite with the two treadles form thc baseof the triangle. Then, if the c rank-pinibe revolved, it will be seenthat the treadles will rise and fall at unequal times, in proportion tothe distance the treadles are apart, and the length of the pitmen; Asboth pitmen cannot be on dead-centres at the same time, there ispractically no dead-centre to the operator, consequently the machine maybe started or stopped at any poin/t of its revolution, and may be runas. slow as may be required, or the motion may be reversed instantly,all by the feet, without the interposition of the hand, to say nothing lof the great saving of power.

It is this peculiar oscillating motion of the treadles that affords theoperators-oi` sewing-machines Such relief from the dull, hard,monotonous motion, so injurious 'in all ordinary machines with singlepitmen or trcadlcs; neither is the motion of the treadles like anydouble-crank machine.

To enable others skilled in the art to mal-e and use my invention,-Iwill proceed to describe its construction and operation.

Figure 1 is an elevation, showing the manner of connecting the twopitinen at the points 3, 4, 5.

Figurel shows a front view of a crank-wheel, K,lwith itsconnection-rods, attached to the two treadlcs t t3. 1 2 3 4, the circleformed by the revolution of the crank-pin.'

The treadlest t2 are hung on an ordinary cross-har, 16, parallel or atan angle to correspond with the natural angle ofthe foot, say, atan'angle of {ive degrees to thc cross-har 1C.

Starting from the upper centre at 1,the triangle a b e is formed withthe hase, b c, parallel with a horizontal line drawn through the centreof the crank-wheel K. Then turn the crank-pin to the right one-quartercircle, i at 2; the saine triangle is maintained, but the hase is notnow horizontal or parallel to the line drawn through the centre oi' thecrank-wheel, but is at an angle to the same, as shown by the red lines qq. The throw of the crank has caused the toc of the treadlc t to descendfurther and faster than the treadle t2, and, when thc crank-pin hasreached the lower centre at 3, the base will again hc horizontal, as inthe upper centre.

The ascent of the crank-pin to 4, on the threequarter circle, will beexactly the reverse of the first quhrter baserline q g.

To shew the operation more fully, the geometrical figure 4 is drawn,with the angles exaggerated. Bcginning, as before, at the upper centre,we have the triangle a b'c. A-t a quarter revolution to2, the two pointsb and c are made to descend in perpendicular lines b h and c z', whichwill throw the triangle into the position shown by the red lines 2 ef,the point b having travelled about twice the distance ofthe peint e inthe sam'e time.

When the crank-pin a is moved down through to the half circle or lowercentre, the points e andf arrive at the bottom at the same time, but thepoint c has now moved about three times further inthe same time than itdid in the first quarter, and about twice as fast as the `pointf, thereverse of the time and motion in the first quarter. In ascending fromthe' lower centre to the upper centre, the motions and times are alsothe reverse of the iirst half circle a 2 3. i

Figure 3 is a modification of the same when the crank-pin is at rightangles with the treadles t t. In this 'f-fgure the treadle t has a longgoose-neck, w, which projects back and around, so as to bring the twopoints m ,and n parallel to the face of the crank-wheel K, better shownin fig. 6. i

I claim as my invention- 1. The use of two connection-rods, for drivingsewing-machines or analogous machines, .when the two connection-rodsform the two legs of a triangle, the crank-pin being the apex of saidtriangle, and when the other two ends of the connection-rods that formthe legs of the triangle unite with two separate treadles or levers, tooperate substantially as set forth. l

2. The use of two independent treadles or levers to revolve a.crank-shaft or wheel, when the two treadles are connected to the samecrank-pin by two connection-rods, substantially as herein set forth.

' ALONZO HITCHCOCK.

Witnesses:

W. S. TIsDsLE, C. McDoNALD.

